B4 Islands and community ecology

Question 1

Ecological community

Answer 1

Essentially a set of species that co-occur at a particular place and time, normally with distinct trophic levels. Assemblage (subset of organisms in that community, like taxonomic group or function) is often relatively interchangeable.

Question 2

Factors (build up + maintenance of species)

Answer 2

Competition, predation, disturbance
Local factors, short time scales

Question 3

Assembly

Answer 3

Takes a lot of time, including evolution (speciation) and dispersal from other localities.

Over time = a diverse assortment of species which make up new communities.

Question 4

Communities

Answer 4

Individual patches in a regional pool of species.
Local and regional species richness are usually positively related, local speciation can drive the diversity up over all.

Question 5

Islands

Answer 5

Land surrounded by water, isolated = easy to study interactions. Provide natural replicates in natural communities (like an archipelago). This means we can look for patterns and rules between each isolated island in a small area.

Question 6

Source pool (adjacent land mass to island)

Answer 6

An island close to an adjacent mainland means immigration would dominate the increase in diversity. But if the island is further away = speciation on island is main point of diversity.